<body>
  <div class="list">
    <ul>
      <li>ONE</li>
      <li>TWO</li>
      <li>THREE</li>
    </ul>
  </div>
  <div class="add">+添加</div>
  <script src="jquery-1.12.4.min.js"></script>
  <script>
    $('.add').click(function () {
      var str = '<li>FOUR</li>';
      $('.list li:last-child').after(str);
    });
  </script>
  <a href="../首页/page11.html">
    <h2>返回上一页面</h2>
  </a>
</body>